A transformer is static electrical equipment used to transform the AC voltage and current and transmit the AC electrical energy. It is based on the principle of electromagnetic induction to achieve the transmission of electrical energy. Transformers can be divided into power transformers, test transformers, instrument transformers, and special-purpose transformers: power transformers are necessary equipment for power transmission and distribution, power user distribution. Test transformers are equipment for withstanding voltage (boost) tests of electrical equipment; instrument transformers are used for electrical measurement and relay protection (PT, CT) of power distribution systems.
The electrical transformer is one of the main pieces of equipment of the power plant and substation. The role of the transformer is multifaceted not only to raise the voltage to send electricity to the power area but also to reduce the voltage for all levels of use, to meet the needs of electricity. In short, the step-up and step-down voltage must be completed by the transformer. In the process of power system transmission of electrical energy, will inevitably produce voltage and power loss of two parts, in the transmission of the same power voltage loss is inversely proportional to the voltage. Power loss is inversely proportional to the square of the voltage. The use of transformers increases the voltage, reducing the transmission losses.
A transformer is composed of two or more coil windings wound on the same core, the windings are linked by the alternating magnetic field and work according to the principle of electromagnetic induction. The transformer installation location should be considered for easy operation, maintenance, and transportation, and at the same time should choose a safe and reliable place. The rated capacity of the transformer must be selected reasonably when using the transformer. When the transformer is running at no load, it needs to use a large amount of reactive power. This reactive power is to be supplied by the power supply system. Transformer capacity if you choose too large, not only increases the initial investment but makes the transformer long-term no-load or light-load operation, so that the proportion of no-load loss increases, power factor decreases, network losses increase so that the operation is both uneconomic and unreasonable. Transformer capacity selection is too small, which will make the transformer long-term overload, easy to damage the equipment. Therefore, the rated capacity of the transformer should be selected according to the needs of the electrical load, should not be too large or too small.